To best comprehend cellular behaviour and how it determines cell migration in metastatic cancer, the research described here has focused on cell mechanics. The signalling pathway involving Rho-associated kinase (ROCK) has emerged as being the main regulator for the cellular cytoskeleton and actomyosin contractility that play key roles in metastatic cancer formation. In this thesis, an examination is made of how the cellular properties intertwine as ROCK is overexpressed. In research towards being able to measure and describe the viscoelastic properties of a cell that are associated with cell mechanics, over a wide range of timescales, a novel AFM force indentation data analysis method was applied. In particular, as part of this study, pancreatic ductal adenocarcinoma (PDAC) cells were overexpressed with ROCK, and the influence of ROCK activity on cell’s elastic and viscoelastic properties were quantified. It was found that when ROCK activity was overexpressed in cells, their elasticity decreased while their viscosity remained unchanged. These properties had a direct correlation with the activity of ADF/cofilin - the proteins downstream of ROCK. This meant that with overexpression, more stable actin bundles were present along with their inward stresses generated by the actomyosin contraction. This is consistent with an increased level of compressive forces within cells. Collective compressive forces between cell-cell are associated with the packing of cells that decreases cellular response. To further understand the role of ROCK activity in cancer invasion, a microfluidic device was created to mimic cell migration through tissue. The device consists of precisely defined microchannels with dimensions chosen to hinder and confine the cells in a manner similar to that found in a physiological environment. It was found that overexpressed ROCK1 cells in the confinement had notable decrease in cell size and motility. Along with this decrease in mechanical properties, observations also gave rise to questions about the connection between these properties that remain to be answered.

Airport terminals are characteristic for the large and open spaces with diverse and transient population. They are designed predominantly as indoor spaces while the overwhelming majority is people in transient conditions. Dressing code and activity, along with dwell time and overall expectations are differentiating factors for variations in thermal requirements between passengers and staff. The diversity of spaces and the heterogeneous functions across the different terminal zones further contribute to this differentiation, which results in thermal comfort conflicts and often in energy wastage. Understanding such conflicts and the comfort requirements can improve thermal comfort conditions while reducing the energy consumed for the conditioning of these energy-intensive buildings. Through extensive field surveys, the study investigated the thermal comfort conditions in three airport terminals of different size and typology. The seasonal surveys included extensive environmental monitoring across the different terminal areas and over 3,000 questionnaire-guided interviews with passengers, staff, well-wishers and other short stay visitors. The findings demonstrate a preference for a different thermal environment than the one experienced and that thermal neutrality lies at lower temperatures. The comfort requirements for passengers and staff are evaluated and shown to differ significantly. Neutral temperature for passengers is lower by 0.6 - 3.9 °C. In accordance with the neutrality discrepancies, passengers prefer cooler temperatures than staff by 0.4 - 2.0 °C. Employees have limited adaptive capacity that leads in a narrower comfort zone, whereas passengers consistently demonstrate higher tolerance of the thermal environment and a wider range of comfort temperatures. Furthermore, the findings highlight the complex nature of thermal comfort in airport terminals, where the desired thermal state for more than half the occupants is other than neutral and a multitude of design and operational characteristics influence the indoor environment.

Protecting Cloud services located within the Cloud Computing centre easily would be a significant advantage in the current Cloud computing market. However, the existing encryption system all process a notable weakness that the private key must be stored locally, so could be accessed and used to break the encryption. To solve this problem, a novel technology has been investigated that recompose the private key by using the properties and behaviours extracted from a Cloud server during execution. This thesis will investigate the feasibility of this approach by analysing simple online programs which would typically form the basis or components of larger systems and thereby indicate, by the ability to distinguish such simple systems, which larger real world practical systems may also be distinguished. The private key does not need to store in the system, which this paper has proved such a system is feasible to be applied in the current encryption system.

The principle aims of this thesis were to investigate the influence of intrinsic navigational cues in virtual environments and video games. Modern video games offer complex environments that may reflect real world spaces or represent landscapes from fantasy and fiction. The coherent design of these spaces can promote natural navigational flow without the requirement for extraneous guidance such as maps and arrows. The methods that designers use to create natural flow are complex and stratified utilising principles rooted in urban architectural design and navigational cues that are intrinsic to real-world wayfinding scenarios. The studies presented in this thesis analysed not only these commonly used architectural cues but also the potential for the reinforcing of these cues by the addition of lighting, visual and auditory cues. The primary focus of this thesis was a systematic and quantitatively rooted analysis of the impact lighting has on navigation and the levels at which variance in lighting makes a quantifiable difference to navigational choices within a virtual environment. The findings of this thesis offer clear guidance as to the influence that lighting has within virtual environments and specifies that thresholds at which the inclusion of guidance lighting begins to affect navigational choices and the levels that players become conscious of these cues. The thesis also analyses the temporal thresholds for the detection of changes in contrast, hue and texture within an environment. The relationship of other intrinsic cues such as the potential reinforcement or cue competition effects of both audio and other visual cues, for instance motion are quantitatively analysed. These data were reflected in the form of a series of heuristic design principles that augment those that underpin architectural and environmental design considerations by for instance suggesting levels of saliency for lighting cues or reinforcing existing cues via supporting audio guidance.

The modern society is in the transition process from the Information Age to the Interaction Age so the attitude of academics and students towards Internet use is continuously changing. This study aims to investigate the attitudes of lecturers and students from Al-Zawiya University (AZU), Libya, towards the use of Internet technology for academic purposes and to formulate a set of recommendations for upgrading the quality and effectiveness of ICT implementation within the School of Engineering from AZU. The action research approach is used to develop a novel framework for increasing the effectiveness of ICT implementation in AZU. The framework aims to improve the Internet skills of lecturers and students, increase the impact of the Internet on their academic efficiency, solve the problems they face while using the Internet, and increase their satisfaction with the Internet facilities provided by AZU. This new framework is built on the basis of different existing models and frameworks (a two-dimensional model for ICT integration in education, the ASSURE model, an framework for HE internationalisation, the ICube model for teaching and learning activities in modern Higher Education institutions). The study includes an analysis of existing Internet use by academic staff and students which looks at various features of Internet usage, including purposes for using the Internet and users’ level of satisfaction with the Internet facilities provided by the university. The SPSS package is employed for qualitative analysis of sixty students’ answers to the questionnaires and shows that people’s skills, computing resources and infrastructure influence the efficacy of integrating computers into HE. Semi-structured interviews are used to determine the attitudes of twelve academics towards use of the Internet in two departments – Department of English Language (DEL) and Department of Electrical Engineering (DEE). The qualitative analysis of academics’ responses identifies the cognitive, performance and affective components of their outlook towards use of the Internet for teaching and research. In addition, the relationship between their answers and the research hypotheses shows that a combination of individual and social factors affects users’ perspectives regarding Internet usage. Finally, a set of recommendations for the enhancement of ICT implementation within the School of Engineering at Al-Zawiya University in Libya is formulated, aiming to enhance the quality of teaching, learning and research activities and the level of students’ satisfaction with the technology-enhanced approach to learning. The findings of this thesis might be of interest to managers, academics and other people involved in the design and development of strategies for ICT implementation in Libyan universities and similar developing countries.

The cumulative global photovoltaic (PV) capacity has been growing exponentially around the world, especially due to the installation of grid connected photovoltaic (GCPV) plants. Fault detection and analysis are important for the efficiency, reliability and safety of solar photovoltaic (PV) systems. Even This thesis reports the results of the research work conducted to invent novel fault detection algorithms and evaluate their deployment in multiple existing PV installation, and empirically validate their performance. A major contribution of this thesis is the development of PV fault detection algorithms based on two indicators named power ratio (PR) and voltage ratio (VR). Both ratios are used to identify the type of the fault that occurs in the PV modules, in PV string, and/or in maximum power point tracking (MPPT) unit. Three AI based algorithms were also used to detect faults in PV modules. The first algorithm uses six regions of the power and voltage ratio in order to detect faults in PV systems. The average detection accuracy for the algorithm is equal to 94.74%. However, Mamdani Fuzzy Logic system has been used to enhance the occurrence of fault detection in the PV installations which resulted in an increase to 99.12%. The second proposed PV fault detection algorithm detects defective bypass diodes in PV modules using Mamdani Fuzzy Logic. Whereas, a third PV detection algorithm is based on artificial neural networks (ANN) networks. Four different ANN models have been modelled, which can be classified as follows: - 2 inputs, 5 outputs using 1 hidden layer - 2 inputs, 5 outputs using 2 hidden layers - 2 inputs, 9 outputs using 1 hidden layer - 2 inputs, 9 outputs using 2 hidden layers The output results for the last ANN network had the highest overall fault detection accuracy of 92.1%. In this thesis, the development of two hot spot mitigation techniques used in PV modules will be discussed. These techniques are capable of enhancing the output power of PV modules which are affected by hot spots and partial shading conditions. The detection of hot spots was captured using i5 FLIR thermal imaging camera. Finally the thesis describes the impact of PV micro cracks on the output power of PV modules. A new statistical analysis approach using T-test and F-test was used to identify the significance impact of the cracks on the output power performance of the PV modules. This is developed using LabVIEW software.

With dwindling worldwide petroleum supplies, there is an ever increasing pressure on the oil industry to develop new reservoir recovery mechanisms or maximise the effectiveness of those currently utilised. Fluctuations of reservoir recovery as a result of nearby seismic activity has been observed, initiating a range of studies into what is causing this effect. The generation of ultrasonic wave fields due to the dispersion of seismic wave fields as they travel through saturated porous rock has been shown, both analytically and experimentally. The feasibility of these generated ultrasonic waves being capable of this observed modification to reservoir is investigated. For the initial stage of this research, the feasibility of changing the behaviour of fluid in rock using an ultrasonic field is considered. Research into the interaction between acoustic waves, the porous rock and the pore fluid indicates two key areas of permeability enhancement - increasing rock permeability and modifying the fluid behaviour within the pores. By increasing the permeability of the rock, previously unobtainable sources may be recovered and less energy would be necessary to obtain these reserves. Cavitation erosion or localised rock weakening due regions of high stress resulting from complex internal wave interactions are the two mechanisms proposed to increase permeability. Modification of the relative fluid behaviours within the rock as a result of mechanical agitation of the fluid from peristaltic transport and cavitation bubbles generated due to the acoustic field was explored. Sandstone cores saturated partially with tap water were placed in a degassed fluid and a low or high acoustic field applied. Tensile strength measurements are taken following exposure to the acoustic field and measurements compared to control samples. Samples were weighed prior to and following testing to determine fluid and gas motion between the surrounding fluid and pore volume. Samples exposed to the low amplitude acoustic pressure field showed no change in tensile strength when compared to control samples. The high pressure acoustic field caused samples to have an increase of strength when compared to the control batch of samples. The partial saturation of the samples exposed to the acoustic pressure field showed an increased in mass following exposure. An exchange of gas bubbles trapped within the pores and fluid with the surrounding degassed water explains this mass increase during testing.

Monolithically integrating multiple sensing technologies shows a great potential to perform quantitative measurements for multiple biomarkers of diseases and also provide more insight towards one single biochemical event. The localised surface plasmon resonance spectroscopy measures the change in the refractive index arising from the molecular adsorption on the metallic nanostructures. Acoustic sensors, such as surface acoustic wave sensor and quartz crystal microbalance, measure the variation of its mechanical oscillation caused by the sum of the deposited molecules and the solvent coupled to the adsorbed molecules. Both techniques are known independently as having applications in in-situ, label-free sensing and analysis of biological binding reactions. Due to their complementary properties, the integration of both can prove to be a valuable tool for studying biomolecules on sensing surface. This thesis reports on the development of a hybrid biosensing device that integrates localised surface plasmonic sensing and acoustic sensing technologies. Gold nanodisk arrays as localised surface plasmon resonance sensing device was studied in visible region using three substrates: borosilicate glass, lithium niobate and quartz. The design, simulation, fabrication and characterisation of the gold nanodisk arrays, and the sensing performance optimisation were investigated using glass substrate. Lithium niobate, as a piezoelectric material has surface acoustic wave compatibility and this study can pave the way towards the development of hybrid sensing devices. The study on lithium niobate demonstrated the feasibility of a localised surface plasmon resonance device utilising a high refractive index, birefringent and piezoelectric substrate. Using quartz as the substrate, the design and fabrication of a hybrid sensor were performed, which integrated localised surface plasmonic resonance into a quartz crystal microbalance for studying biochemical surface binding reactions. The coupling of localised plasmon resonance nanostructures and a quartz crystal microbalance allows optical spectra and quartz crystal microbalance resonant frequency shifts to be recorded simultaneously, and analysed in real time for a given surface adsorption process. This integration has the potential to be miniaturised for application in point-of-care diagnostics.

Designs for geostationary (GEO) solar power satellites (SPS) are extremely large in scale, more than one order of magnitude larger than the International Space Station. In this thesis a detailed study of the orbit dynamics of SPS is performed. Analytical equations, derived by the process of averaging of the SPS equations of motion, are used to determine the long-term orbital evolution. Previous SPS studies have simply assumed a GEO as the operational orbit, and then designed control systems for maintaining the orbit within acceptable nominal values. It is found that an alternative SPS orbital location known as the geosynchronous Laplace plane orbit (GLPO) is superior to GEO in many aspects. An SPS in GLPO requires virtually no fuel to maintain its orbit, minimises the risk of debris creation at geosynchronous altitude, and is extremely robust operationally, i.e. loss of control is inconsequential. The GLPO SPS requires approximately 10^5 kg less fuel per year compared to a GEO SPS while providing near equivalent power delivery. Although savings in orbit control are achieved, depending on the mass distribution of the SPS, attitude control costs may be incurred by placing an SPS in GLPO. Consideration of the attitude dynamics of SPS has motivated the development of a model for the rotational dynamics of a body which includes energy dissipation and the effects of external torques. Multiple spring-damper masses are used to provide a mechanism for energy dissipation. This rotational dynamics model is used to assess the naturally stable attitude configurations of a SPS design in geosynchronous orbit subject to gravity gradient torque. It is found that for a large planar array, a dynamically stable configuration requiring nominal orbit-attitude control is possible. This involves rotating around the maximum axis of inertia at the orbit rate, with the minimal axis aligned in the radial direction. It will be shown that a SPS in this configuration while in GLPO requires virtually no orbit or attitude control. The most significant result of the research in this thesis is proving that a SPS can operate in GLPO with nominal orbit control and yet still deliver almost equivalent power to the Earth’s surface as the same SPS would in a controlled GEO.

Most desired applications for planning and scheduling typically have the characteristics of a continuous changing world. Unfortunately, traditional classical planning does not possess this characteristic. This drawback is because most real-world situations involve quantities and numeric values, which cannot be adequately represented in classical planning. Continuous planning in domains that are represented with rich notations is still a great challenge for AI. For instance, changes occurring due to fuel consumption, continuous movement, or environmental conditions may not be adequately modelled through instantaneous or even durative actions; rather these require modelling as continuously changing processes. The development of planning tools that can reason with domains involving continuous and complex numeric fluents would facilitate the integration of automated planning in the design and development of complex application models to solve real world problems. Traditional urban traffic control (UTC) approaches are still not very efficient during unforeseen situations such as road incidents when changes in traffic are requested in a short time interval. For such anomalies, we need systems that can plan and act effectively in order to restore an unexpected road traffic situation into a normal order. In the quest to improve reasoning with continuous process within the UTC domain, we investigate the role of Model Predictive Control (MPC) approach to planning in the presence of mixed discrete and continuous state variables within a UTC problem. We explore this control approach and show how it can be embedded into existing, modern AI Planning technology. This approach preserves the many advantages of the AI Planning approach, to do with domain independence through declarative modelling, and explicit reasoning while leveraging the capability of MPC to deal with continuous processes. We evaluate the possibility of reasoning with the knowledge of UTC structures to optimise traffic flow in situations where a given road within a network of roads becomes unavailable due to unexpected situations such as road accidents. We specify how to augment the standard AI planning engine with the incorporation of MPC techniques into the central reasoning process of a continuous domain. This approach effectively utilises the strengths of search-based and model-simulation-based methods. We create a representation that can be used to capture declaratively, the definitions of processes, actions, events, resources resumption and the structure of the environment in a UTC scenario. This representation is founded on world states modelled by mixed discrete and continuous state variables. We create a planner with a hybrid algorithm, called UTCPLAN that combines both AI planning and MPC approach to reason with traffic network and control traffic signal at junctions within the network. The experimental objective of minimising the number of vehicles in a queue is implemented to validate the applicability and effectiveness of the algorithm. We present an experimental evaluation showing that our approach can provide UTC plans in a reasonable time. The result also shows that the UTCPLAN approach can perform well in dealing with heavy traffic congestion problems, which might result from heavy traffic flow during rush hours.